The Plasmodium Genome Database <http://PlasmoDB.org> was established in 2000, to expedite access of the malaria research community to genomic-scale datasets, beginning with the reference genome sequence for P. falciparum. PlasmoDB incorporates finished and unfinished sequence from the P. falciparum genome project, genetic & optical mapping data, curated annotation of finished sequences provided by the sequencing centers, automated analyses of DNA and predicted genes/protein sequences using multiple algorithms, comparisons with GenBank/EMBL and other databases, unfinished genomic sequences and Plasmodium ESTs from various species, and expression data from SAGE and microarray projects. All information is incorporated into a comprehensive relational database, facilitating user queries. The on-line database receives up to 13,000 hits per day, from users in more than 100 countries, and many thousands of CD-based copies have been distributed worldwide. PlasmoDB was initially supported through a seed grant from the Burroughs Wellcome Fund; this application seeks funding to maintain and extend the database, for the benefit of the research community at large. Database enhancement is an ongoing research and development project, resulting in tools that are broadly applicable to genomic-scale datasets for any organism. Specific aims seek to: 1. Enhance access to PlasmoDB as a community resource, including development of an improved web interface for relational queries. 2. Provide a mechanism for community input and response, including implementation of comment forms (for the web site, gene annotation, and other data types), tracking responses to comments, and posting comments and responses at PlasmoDB. 3. Expand the depth and scope of data available, including expression profiling and proteomics data, etc. 4. Provide comparative analyses of Plasmodium species, facilitating identification of genes and regulatory elements, genetic mapping, evolutionary studies, etc. The overall goal of this project is to develop and maintain a database that expedites biological discovery, including the identification of drug targets and vaccine antigens useful in the fight against malaria.